Page 73 - Laboratory Manual in Physical Geology
P. 73
Total Length of the Percentage of each of
Total Length
Lithospheric Plate Boundary Type three main plate the three main plate
(kilometers)
boundary types boundary types
Ocean-ocean convergent boundaries 17,449 Convergent Convergent
Ocean-continent convergent boundaries 51,310
Continent-continent convergent boundaries 23,003
Continental rift divergent boundaries 27,472 Divergent Divergent
Mid-ocean ridge divergent boundaries 67,338
Ocean transform fault plate boundaries 47,783 Transform Transform
Continental transform fault plate boundaries 26,132
2. Do you think Earth’s size is increasing (expanding), decreasing (shrinking), or staying about the same in size? Justify your
answer by citing evidence from your work above.
2
3. Peter Bird also calculated that Earth’s lithosphere is being created at a rate of 3.4 km /yr and being destroyed at a rate of
2
2
3.4 km /yr. At these rates, and the fact that Earth’s surface area is 510,000,000 km , how long would it take to recycle
Earth’s entire lithosphere? Show your work.
B. REFLECT & DISCUSS Do you think that plate tectonics is being caused by a change in Earth’s size, or something else? If
something else, then what do you suggest? Explain.
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